rate of change

Question

A raindrop falls to the ground from the height 's' meters. After 't' seconds the raindrop is 's' meters above the ground where s(t)= 120 - 2t^2. Find the rate of change in height 's' when t= 4 seconds. Find answer using limiting strategy. 

Answer 1

V(4) = lim as h→0 [s(4+h)-s(4)]/h

 

V(4) = lim as h→0 [120 - 2(4+h)² -120 + 2(4²)]/h

 

V(4) = lim as h→0 [-16h - 2h²]/h

 

Can you finish it from here?